SQUID (superconducting quantum interference device) magnetometers have been used to study the magnetic activity associated with spike discharges occurring in interictal periods in patients with temporal lobe epilepsy. Magnetic field maps associated with specific spike discharges were obtained from measurements made with the SQUID at various locations on the skull. Mathematical models, which accounted for the head shape of the patient and the orientation of the SQUID, were developed to calculate the predicted magnetic field maps. These comparisons of the experimental and theoretical data indicate close agreement in some areas, but significant deviations in others, that are not explained by skull topography alone. A seven- channel SQUID has been obtained and is being evaluated.